package demo2;

public class Computer {
    public void powerOn() {
        System.out.println("打开电脑");
    }

    public void powerOff() {
        System.out.println("关闭电脑");
    }

    public void useDevice(IUSB usb) {
        usb.openDevice();
        if (usb instanceof Mouse) {
            ((Mouse) usb).click();
        } else if (usb instanceof KeyBoard) {
            KeyBoard keyBoard = (KeyBoard) usb;
            keyBoard.inPut();
        }

        usb.closeDevice();
    }

    public static void main(String[] args) {
        Computer computer = new Computer();
        computer.powerOn();

        computer.useDevice(new Mouse());
        computer.useDevice(new KeyBoard());

        computer.powerOff();
    }
}
